Octane sensitive dispenser blending system

ABSTRACT

An octane sensitive blending dispenser for fluids, particularly for fuel dispensers. The dispenser controls component pumps according to octane data measured by octane meters. In one form of the invention octane measurements are taken within the input lines connected to the dispenser from fluid storage tanks. Control of the component pumps is accomplished by determining the difference between the desired blend octane and the observed blend octane and adjusting the pumps so as to more closely blend the desired fluid.

This Application is a Division of Ser. No. 08/921,117 filed Aug. 29,1997 and also claims the benefit of Provisional No. 60/028,220 filedOct. 10, 1996.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The field of the invention is that of blending dispensers for liquids.More particularly, the field is that of blending dispensers capable ofdispensing a variety of different octane fuels.

2. Description of the Related Art

In liquid dispensing devices, for example gasoline fuel pumps differentgrades of gasolines are conventionally mixed to provide a specificblend. Using two gasoline sources, one supply tank containing gasolinehaving a first octane rating, for instance, 95, and the other supplytank containing gasoline having another octane rating, for instance, 83,conventional dispensers produce gasoline blends having a desired octanerating in the range of 83 to 95 by measuring the volume of each octanebeing dispensed and adjusting accordingly.

The following example uses 83 and 95 octane gasolines as the componentfuels because they represent a common prior art range of octanes;however, a variety of ranges of octanes have been used to mix andprovide blends of gasoline. For example, gasolines of various octaneratings can be provided by mixing component gasolines in the followingpercentages:

    ______________________________________                                        Octane       % of 83 Octane                                                                           % of 95 Octane                                        ______________________________________                                        83           100        0                                                     87           67         33                                                    89           50         50                                                    91           33         67                                                    95           0          100                                                   ______________________________________                                    

In prior art systems, such as U.S. Pat. No. 4,876,653, issued toMcSpadden, a proportional control system has been used to check theblending ratio periodically by observing the instantaneous flow rates ofthe two component streams of fluid (e.g. from the 83 and 95 octanetanks). An electronic controller observes the instantaneous flow ratesby receiving signals from flow meters in the two flow lines. When theinstantaneous flow rates substantially deviate from those needed toprovide the desired mixture, the valves which control the componentstreams are adjusted accordingly. This results in a dispenser whichtends to deliver an instantaneous blend ratio equal to the desiredmixture only after a significant portion of the desired quantity of fuelhas been dispensed, assuming that liquid pressure remains relativelyconstant. Thus a significant quantity of the dispensed fuel may have anincorrect blend or mixture. However, such proportional control systemsonly correct for errors in the instantaneous flow rate and do notaccount for errors in the fuel which has already been dispensed so thatthe total amount of dispensed fuel will be a desired blend. Moreover,such systems are dependent on having components stocks which are of thecorrect octane. If the stock fluids are not of the correct octane, whichis often the case, the resulting mix will be correspondingly incorrect.

More recent prior art, such as U.S. Pat. Nos. 5,038,971 and 5,125,533,both assigned to the present assignee, greatly improve on this conceptby measuring the flow rates of two component streams and using aproportional-integral-differential (PID) control algorithm. The PIDcontrol algorithm lessens the amount of deviation from the desiredratio, and results in a blend closer to the actual desired octane.However, such a system still assumes the component fuels possess theirclaimed octane, and the octanes of each component fuel are not actuallymeasured but rather the volume of each component fuel is adjusted if theflow rates diverge past certain parameters.

SUMMARY OF THE INVENTION

The present invention is an octane sensitive dispenser blending systemwhich continuously measures the octane of the component fuels andadjusts the flow rates of the component fuels in order to reach thedesired final octane During each dispensing session, the flow rates ofeach component fuel are continuously corrected based on signals receivedfrom octane sensors stationed directly in the fluid stream. Thecorrection required is performed by having a microprocessor compare theuser-selected, desired octane to the actual octane being dispensed andadjusting the component flow rates accordingly.

The present invention utilizes two component fuel tanks, wherein onefuel tank contains fuel of relatively low octane, and the other tankcontains fuel of relatively high octane. In the exemplary embodiment, asthe fuel is dispensed from each of the fuel tanks, separate octanemeters measure the actual octane of each component fuel as they aredispensed. These octane meters in turn send electric signals to aprocessing unit which compares the actual octanes being combined to theoctane selected by the user. Based on calculations using both the actualoctane being dispensed and the octane selected by the user, theprocessing unit will then send a signal to the pumps controlling eachdispensing tank. These pumps then adjust the flow rate of each componentfuel based on the signals received from the processing unit and theresulting blend will be fed to a nozzle or other dispensing device.

In the present invention, only two supply tanks are needed to provide avariety of blends ranging from the octane ratings of the low octane fuelto high octane fuel. Thus a fuel dispensing station needs only twosupply tanks to provide a variety of octane blends, rather than one tankfor each octane blend dispensed which would add to the cost of thestation. Also, because of the expense involved in monitoring the supplytanks for environmental reasons, the cost of maintaining theinstallation is lowered by accurately and individually measuring theamount of fuel, such as gasoline, supplied by each tank. Requiring onlytwo tanks for numerous blends lowers the cost necessary to build agasoline dispensing installation and lowers maintenance costs as well.Also, the present invention is adaptable to a variety of sizes ofinstallations, from one dispenser and two small tanks to a multiplicityof dispensers and two or more large tanks.

One advantage of the present invention is that it provides a dispenserwhich measures the octane of each component fuel as it is dispensed toprovide more accurate octane data to the processing unit.

Another advantage of the present invention is that it provides adispenser which calculates pump flow rate adjustments according to theactual octane of the component fuels dispensed, and the octane selectedby the user, to eliminate the need to combine more of the higher octanefuel to ensure the resulting blend has a sufficiently high octane.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a schematic diagram of the octane sensitive blending dispenserof the exemplary embodiment of the present invention;

FIG. 2 is a schematic diagram of an alternate embodiment of the presentinvention.

Corresponding reference characters indicate corresponding partsthroughout both views. The exemplifications set out herein illustratetwo embodiments of the invention and such exemplifications are not to beconstrued as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, the exemplary embodiment of the present invention isgenerally depicted as dispenser unit 10. Controller board 12 receivessignals from octane meters 14 and 16 and operates variable pumps 18 and20. Nozzle 22, via Y connection 24, receives the output of variablepumps 18 and 20, and mixes and dispenses the component fuels. Variablepump 18 receives fuel from supply tank 26, with meter 14 monitoring theoctane of the fuel supplied to variable pump 18. Octane meter 14 iscoupled to controller board 12 by line 15 and sends signals through line15 to board 12 which represent the octane of the fuel flowing throughpump 18. Possible octane sensing technology may include near infrared,infrared mass spectrometry, or optical transmission detection of tracecompounds, materials and dyes.

Similarly, supply tank 28 provides fuel to variable pump 20, with octanemeter 16 measuring the octane of the fuel flowing through pump 20 andelectronically transmitting that octane measurement data to controllerboard 12 via line 17. Pumps 18 and 20 receive control signals fromcontroller board 12 via control lines 19 and 21, respectfully.Alternately, the functions of pumps 18 and 20 can be combined in asingle pump in which one passageway opens while the other closes.

An alternative embodiment of the present invention is shown in FIG. 2.Dispenser unit 32 has two sets of supply tanks flow meters, pulsers, andvalves coupled to an output nozzle. Specifically, supply tanks 34 and 36are coupled to flow meters 38 and 40, respectively. For purposes of thisexample, supply tank 34 contains low octane (Product 1, e.g. 83 octane)and supply tank 36 contains a high octane gasoline (Product 2, e.g. 95octane). Flow meter 38 and 40, which in the preferred embodiment arepositive displacement meters such as piston meters, measure the volumeof gasoline supplied by its respective supply tank, and are coupled topulsers 42 and 44, respectively. To keep a tally of the volume ofgasoline measured by the respective meters, registers within controllerboard 45 count pulses received from pulsers 42 and 44 attached to meters38 and 40. Each pulse represents a predetermined amount of fuel. Blendvalve 46 serves as the conduit between supply tanks 34 and 36,respectively, incorporating a Y connection 50 to provide nozzle 51 withappropriate volumes of component gasolines. Between nozzle 51 and blendvalve 46 is disposed an octane meter 54 for measuring the octane out ofthe output gasoline blend. Octane meter 54 sends a signal to controller45 dependent on the measured octane of the output blend.

A microprocessor (not shown) within controller board 45 is electricallycoupled to pulsers 42 and 44. Based on the octane selected by the user,the measured octane data from meter 54, and the flow rates of thecomponent fuels, the microprocessor will calculate adjustments in thetwo flow rates and send signals to valve 46 to adjust the flowsaccordingly.

In the exemplary embodiment, the dispensing of fuel will begin when auser selects an octane to be dispensed. The selected octane will beentered on a input panel (not shown) which in turn will transmit anelectric signal to controller board 12. Controller board 12 willcalculate the amount of product 1 contained in tank 26, and product 2,contained in tank 28, which should be combined to result in a fuelhaving an octane corresponding to the octane selected by the user. Toensure that the resulting octane ultimately fed through nozzle 22 is ofthe octane selected by the user, octane meters 14 and 16 willcontinuously measure the octane of the fuels being dispensed from tank26 and tank 28, respectively. This octane data will be transmitted tocontroller board 12 which will continually make calculations dependingon the variations of the octanes being dispensed from tanks 26 and 28and will adjust the flow rates of the two components to result in thedesired octane. Controller board 12 will adjust the flow rates of thetwo components by sending electric signals to pumps 18 and 20 tocorrespondingly adjust the flow rates of each pump.

In the alternative embodiment, the dispensing of fuel will also commencewhen a user selects an octane through the input panel (not shown). Thisselected octane data will be fed to controller board 45 which will inturn transmit electric signals to begin dispensing of product 1 fromtank 34, and product 2 from tank 36. As the component fuels aredispensed, flow meters 38 and 40 will monitor the volume of thecomponent fuels being dispensed by tanks 34 and 36, respectively, andthrough pulsers 42 and 44 will transmit electric signals back tocontroller board 45. If the flow rates of the two components are notsufficient to result in the desired selected final octane, themicroprocessor will adjust the flow rates accordingly by sendingappropriate signals to blend valve 46. Finally, the alternativeembodiment uses octane meter 54 to monitor the octane of the fuel beingdispensed from blend valve 46. This octane data is transmitted tocontroller board 45 which will adjust the flow rate through blend valve46 if necessary.

While this invention has been described as having an exemplary design,the present invention can be further modified within the spirit andscope of this disclosure This application is therefore intended to coverany variations, uses, or adaptations of the invention using its generalprinciples. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains and which fallwithin the limits of the appended claims.

What is claimed is:
 1. A dispenser for blending component fluidsaccording to a desired octane for the blended product, said dispensercomprising:a plurality of fluid conduits, each said fluid conduitcoupled to one of at least two supplies of component fluid to bedispensed there for; a variable valve means coupled to each said fluidconduit for controlling the flow rate at which each said component fluidflows through said respective fluid conduits; a flow meter meansoperatively associated with said fluid conduits for measuring the volumeof said component fluid flowing through each said fluid conduit and forproviding volume signals representative of said volumes; an output meanscoupled to each said fluid conduit for mixing and dispensing saidcomponent fluids; an octane meter means operatively associated withoutput means for measuring the octane of the mixed component fluids andfor providing an octane signal representative of said octane; andcontrol means for controlling the blending and dispensing of saidcomponent fluids, said control means coupled to said flow meter, saidoctane meter and said valve means, said control means includingselecting means for selection of said desired octane blend andcomparison means for comparing a calculated octane with said desiredoctane and for determining a corrected blend ratio, said control meansfurther including adjustment means for adjusting said variable valvemeans in accordance with said corrected blend ration such that theactual octane of dispensed blended fluids is substantially equal to saiddesired octane.
 2. A dispenser for blending component fluids accordingto a desired octane for the blended product, said dispenser comprising:aplurality of fluid conduits, each said fluid conduit coupled to one ofat least two supplies of component fluid to be dispensed there for; avariable valve means coupled to each said fluid conduit for controllingthe flow rate at which each said component fluid flows through saidrespective fluid conduits; an output means coupled to each said fluidconduit for mixing and dispensing said component fluids; an octane metermeans operatively associated with output means for measuring the octaneof the mixed component fluids and for providing an octane signalrepresentative of said octane; and control means for controlling theblending and dispensing of said component fluids, said control meanscoupled to said octane meter and said valve means, said control meansincluding selecting means for selection of said desired octane blend andcomparison means for comparing a calculated octane with said desiredoctane and for determining a corrected blend ratio, said control meansfurther including adjustment means for adjusting said variable valvemeans in accordance with said corrected blend ratio such that the actualoctane of dispensed blended fluids is substantially equal to saiddesired octane.
 3. The dispenser according to claim 2 further includinga flow meter means operatively associated with said fluid conduits formeasuring the volume of said component fluid flowing through each saidfluid conduit and for providing volume signals representative of saidvolumes, said volume signals comprising a plurality of pulses, each saidpulse representing a predetermined volume of fluid.
 4. The dispenseraccording to claim 3 wherein said control means determines saidcalculated octane with said volume signals by dividing the total pulsesrepresenting on said component fuel volume by the total of all pulsesreceived from each said flow meter means.